Pyrimethamine contraindications

Infants (younger than 2 months of age) - Contraindicated, except as adjunctive therapy with pyrimethamine in the treatment of congenital toxoplasmosis. 

I Contraindications Hypersensitivity to pyrimethamine, megaloblastic anemia due to folate deficiency, monotherapy for freafmenf of acufe malaria. 

Sulfonamides are contraindicated in patients with known hypersensitivity or intolerance to any member of this drug femily. Sulfonamides are also contraindicated in pregnancy at term, for nursing mothers, and for infants less than 2 months old becanse they can promote kernicterus in the newborn by displacing bilirubin from plasma proteins. The sulfonamides, pyrimethamine, and trimethoprim are contraindicated in patients with documented blood dyscrasias. 

Sulfonamide and/or pyrimethamine sensitivity, pregnancy, and G6PD deficiency are contraindications. Use in young infants is considered inadvisable the history of an 8-month-old infant with P. falciparum malaria who developed high fever, tachycardia, hypotension, chills, jaundice, and splenomegaly 48 hours after a single parenteral dose of Fansidar (pyrimethamine + sulfadoxine) (SEDA-16, 309) seems to confirm the wisdom of this advice. It has been advocated that Fansidar should not be used prophylactically if exposure to malaria will last less then 3 weeks, in view of the incidence of severe skin reactions during the first month. 

Sulfonamides or sulfones usually account for most toxicity associated with coadministration of these antifolate drugs (see Chapter 43). The combination of pyrimethamine (25 mg) and sulfa-doxine (500 mg) (fansidar) causes severe and even fatal cutaneous reactions in up to 1 in 5000 people. This combination also has been associated with serum sickness-type reactions, urticaria, exfoliative dermatitis, and hepatitis. Pyrimethamine-sulfadoxine is contraindicated in individuals with previous reactions to sulfonamides, lactating mothers, and infants <2 months of age. Administration of pyrimethamine with dapsone (MALOPRIM, unavailable in the U.S.), occasionally has been associated with agranulocytosis. Higher doses pyrimethamine (75 mg daily) used along... 

---